Digital filter designing method, digital filter designing program, digital filter

Inactive Publication Date: 2005-06-02
NSC CO LTD
View PDF4 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0025] Furthermore, according to a still further aspect of the present invention, a high-pass filter and low-pass filter are designed in such a way that the respective pass bands overlap with each other in the pass band of the unit filter having a re

Problems solved by technology

However, the above described conventional filter designing method requires an expert technician to perform design with an immense amount of time and effort, causing a problem that it is not easy to design an FIR filter having a desired characteristic.
Furthermore, even if it is possible to design an FIR filter having substantially a desired characteristic, the number of taps of the designed filter becomes eno

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Digital filter designing method, digital filter designing program, digital filter
  • Digital filter designing method, digital filter designing program, digital filter
  • Digital filter designing method, digital filter designing program, digital filter

Examples

Experimental program
Comparison scheme
Effect test

Example

[0043] Before explaining an embodiment of the present invention, an overview of Japanese Patent Application No. 2001-400673 (hereinafter referred to as “previous application”) already applied by the present applicant will be explained below. According to this previous application, four types of unit filters L1n, L2n, H1n, H2n are created using four types of basic unit filters F0, F1, F2, F3 which will be explained below so as to make it possible to design an FIR filter having a desired frequency characteristic by only combining these unit filters.

[0044]FIGS. 1A and 1B are diagrams showing the four types of basic unit filters F0 to F3; FIG. 1A shows the circuit structure and FIG. 1B shows numeric strings of filter coefficients. As shown in FIG. 1A, in the basic unit filters F0 to F3, five cascade connected D-type flip flops 1−1 to 1−5 delay an input signal sequentially by 1 clock CK at a time. Then, the signals extracted from the input / output taps of the respective D-type flip flops...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

According to a basic unit filter having a predetermined basic numeric string as a filter coefficient, a high-pass unit filter (H15) and a low-pass unit filter (L13) having pass bands having a common center frequency Fc are created. These are connected in the cascade way to design a band pass filter. Characteristic values obtained by combining a few types of unit filters are cancelled by each other. Thus, without pulling out a necessary frequency band and only by the cascade connection of the high-pass unit filter (H15) and the low-pass unit filter (L13), it is possible to extract a superimposed portion as a band pass filter pass band.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a digital filter designing method, digital filter designing program and digital filter, and more particularly, to a method of designing an FIR filter, which comprises a tapped delay line made up of a plurality of delayers and performs multiplying signals of the respective taps several-fold and then adding up the results of multiplication and outputting the addition result. [0003] 2. Description of the Related Art [0004] Some kind of digital signal processing is generally performed in various kinds of electronic devices provided in various fields of communication, measurement, sound / image signal processing, medical care, seismology, and so on. One of the most significant basic operation of the digital signal processing is filtering which extracts only a signal having a necessary frequency band from an input signal in which signal and noise are mixed. For this reason, digital filters a...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G06F17/10H03H17/02
CPCH03H17/0286
Inventor KOYANAGI, YUKIO
Owner NSC CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap